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United States Patent | 5,656,239 |
Stegemeier ,   et al. | August 12, 1997 |
An in-situ method is disclosed for low pressure vaporization and recovery of contaminants from surface and near-surface soil by electrically heating the soil with a pattern of hollow electrodes and pulling a deep vacuum through the electrodes. The surface of the soil is sealed with an impermeable barrier supported by the soil. The contaminants are removed by vacuum distillation in the presence of water vapor at a temperature well below the normal boiling point of the contaminants.
Inventors: | Stegemeier; George Leo (Houston, TX); Vinegar; Harold J. (Houston, TX) |
Assignee: | Shell Oil Company (Houston, TX) |
Appl. No.: | 460403 |
Filed: | June 2, 1995 |
Current U.S. Class: | 422/32; 422/22 |
Intern'l Class: | E02D 031/00 |
Field of Search: | 422/1,22,26,28,32,33 166/248,272 405/128,129,131,248,258 219/10.41,10.57,10.81 |
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Betsy Carpenter, "Superfund, superflop --The progress on hazardous waste: Only $300 billion to go", U.S. News & World Report, Feb. 6, 1989. |